Salvage follow-up integrating PR #30481 (@simplast) and PR #57683
(@catbearlove1-lang) into the unified export surface:
- --format html: standalone self-contained HTML transcript (single
session or multi-session with sidebar), works with all shared filters
and --redact; requires a file output path.
- --only user-prompts: prompt-only export (jsonl records or md sections)
via the shared session_export renderer; the separate export-prompts
subcommand from the original PR is subsumed by this flag.
- AUTHOR_MAP entries for both contributors; docs EN + zh-Hans.
